The present invention relates to a hand scanner input system which reads image data from a recording medium and inputs the data into a storage means.
With reference to FIG. 1, it will be explained how a conventional hand scanner reads image data from a document and inputs the data to a data processor. A document sheet 8 is fixed on a rectangular tablet 2. Tablet 2 has holes 10 arranged at equal intervals along its left side. A rail 1 is attached to the left side of tablet 2. The left end of a ruler 3 is butted on rail 1, and has one through hole.
The operator slides ruler 3, against the rail to align it with the lowest line of sheet 8, and secures ruler 3 with respect to tablet 2 by inserting a stopper 9 into one of holes 10 through the hole of ruler 3. The operator then slides a hand scanner 4 on the edge of ruler 3 to the left until the scanner contacts rail 1. The operator then turns the switch 6 of scanner 4 on and manually moves scanner 4 to the right (in the direction of the arrow) along ruler 3. While being moved in this way, hand scanner 4 scans sheet 8 and simultaneously detects strobe-generating slits 11 which are cut in the edge of ruler 3; thus generating image data signals and strobe pulses. The signals and pulses are supplied from hand scanner 4 to the data processor (not shown) through signal line 7. When scanner 4 reaches the right side of sheet 8, the one-row area scanning ends. The operator pulls stopper 9 out and slides ruler 3 upward along rail 1, bringing ruler 1 into alignment with the next scanning line of sheet 8.
The operator repeats the sequence of operations stated in the preceding paragraph to scan all of the row areas of sheet 8 and input all obtained image data to the data processor (not shown).
The conventional hand scanner needs the assistance of rail 1 and ruler 3 to scan document sheet 8. Further, tablet 2 must have hole 10 to align ruler 3 with every row area to be scanned. The whole system, including rail 1, tablet 2 and ruler 3, as well as hand scanner 4, is complicated and expensive. Moreover, to bring ruler 3 into alignment with every row area and fasten it to tablet 2 is cumbersome and time consuming.
The intervals at which holes 10 are arranged are equal to the width of the scanning surface of hand scanner 4. Hence, when these intervals are different from the pitch at which characters are printed on document sheet 8, hand scanner 4 reads the lower half of each character of one line 12 of sheet 8 in the nth row area-scanning, and reads the upper half of each character of line 12 in the (n+1)th row area scanning. Even if the intervals are equal to the character pitch, the same problem will occur when document sheet 8 is placed on tablet 2 such that the character lines are not horizontally aligned with holes 10. Consequently, the characters reproduced from the data read and input by hand scanner 4 are distorted as shown in FIG. 3. When ruler 3 is horizontally displaced after the nth row-area scanning and before the (n+1)th scanning, the characters reproduced from the data input by scanner 4 are distorted as shown in FIG. 2. Such distorted characters are hard to read and understand.